<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
        "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>

<p id="js">javaScript</p>
<div id="list">
  <p id="se">javaSe</p>
  <p id="ee">javaEE</p>
  <p id="me">javaME</p>
</div>

<script>
  var ee = document.getElementById('ee');
  var js = document.getElementById('js');
  var list = document.getElementById('list');

  var child1 = list.children[0];

  console.log(child1);
  list.insertBefore(js,ee); // 将js插到ee之前

</script>
</body>
</html>